The present research proposal aims to demonstrate and clarify biochemical regulatory mechanisms controlling cellular differentiation during development of the secondary palate. Palatal differentiation may be defined in terms of glycosaminoglycan, collagen, cell surface glycoconjugate, cyclic nucleotide and possibly prostaglandin biosynthesis and can easily be monitored both in organ or cell culture. Preliminary data strongly suggest that palatal cAMP, possibly regulated by prostaglandins, may control the synthesis of palatal extracellular and cellassociated matrix components requisite for palatal differentiation. We therefore propose (1) to characterize the prostaglandin biosynthetic capabilities of palatal mesenchyme by thin-layer chromatography and radioimmunoassay; (2) localize endogenous, prostaglandins during palatal development by immunocytochemistry and (3) to determine the involvement of cAMP and prostaglandins in synthesis of palatal glycosaminoglycans, collagen, medial-edge epithelial glycoconjugates and palatal mesenchymal proliferation. These studies will provide a better understanding of the normal biochemical events underlying development of the secondary palate. Such information is fundamental to meaningful investigations probing etiology of palatal clefting.